The Input Library would optionally replace
occurrences of rn, r, n in input data with whatever the PHP_EOL
value is on your system - if you’ve set $config['standardize_newlines']
to TRUE in your application/config/config.php.

This functionality is now deprecated and scheduled for removal in
CodeIgniter 3.2.+.

Note

The functionality is still available, but you’re strongly
encouraged to remove its usage sooner rather than later.